Deleting a user - how ?

[Andreas Bach Aaen]

I have create a user : Andreas <aba@tbit.dk> (Telebit)
which keys is now expired.
Then I created a new user: Andreas <aba@tbit.dk> (Ericsson Telebit)
with a new key.

How do I delete the first entry completely ?

Or how do I make uid "aba" mean the new entry ?

Regards, 

Andreas Bach Aaen                     System Developer, M. Sc. 
Ericsson Telebit A/S                  tel: +45 86 28 81 76
Fabrikvej 11                          fax: +45 86 28 81 86
8260 Viby J      Denmark              e-mail: aba@tbit.dk